1. Field of the Invention
The invention relates to dental appliances which are used for propping open the mouth to permit the dentist to have a wide and dry field of operation.
2. Description of the Prior Art
In the past, various appliances have been used to isolate or open parts of the mouth to facilitate the performing of dental services. Bite blocks and expansion forceps have been used to hold the patient's jaws open. These devices do not have any provision for protecting the soft tissues of the mouth from injury caused by the patient biting down on them. Nor do they have any provision for saliva removal. Moreover, unlike the present invention, they do not have a flexible frame to which are attached cheek deflectors which displace the cheeks outward when the patient bites down upon the flexible frame. Another common applicance used for isolating parts of the mouth is the rubber dam which consists of a flexible piece of material having holes disposed therein to permit placement down over the teeth into surface contact with the gums so that the teeth protrude through the holes in the rubber dam. Unlike the present invention, the rubber dam does not have a flexible frame having cheek and tongue deflectors attached thereto and the provision for saliva removed. Another appliance is a mouth prop sold by Parkell. This device consists of an oval shaped frame having lip deflectors attached thereto. It does not have provision for saliva ejection or tongue deflection. Moreover, it may only be used to isolate the anterior teeth.
U.S. Pats. No. 24,693, and Nos. 1,868,653, 2,587,008, 2,937,445, 3,078,578 and 3,772,790 disclose dental appliances which are used to facilitate the performance of dental work. None of these appliances disclose a flexible support frame having cheek deflectors which force the patients's cheeks outward away from the field of operation upon compression of the flexible frame by closing of the patient's jaws.
U.S. Pat. No. 3,396,468 discloses a dental appliance having a flexible support frame having a pair of U-shaped frame members which are respectively disposed inside and outside of one half of the upper and lower dental arches. The support frame has provision for the attachment of a rubber dam to isolate the dental arch from the rest of the mouth. A vacuum source may be attached to the lower part of the tubular support frame for drawing saliva inside the tubular frame through a plurality of holes which are disposed in the frame. This appliance differs substantially from the present invention in that it may only be used to isolate one half of the patient's mouth and that it does not have provision for a cheek deflector to force the patient's cheek outward away from the dental field of operation upon closing of the patient's jaws.